I've replaced the spinning gears on the boot screen with this little fella (on a transparent backround)
http://www.xbpro.com/pictures/tux.gif
I've attached the files for anyone who wants them.
UnRar and upload the 8 image files to: /usr/share/enigma2/skin_default/spinner (delete or overwrite the originals)
Walking Tux Files
:)